Super lightweight, a little hard to wrangle
I got the Ultra-Sil Nano Poncho for my walk on the Camino de Santiago in October. I wore it several times – twice during significant rain and twice in significant rain and wind. Overall, it did its job, and I was really glad to have something so lightweight that I could easily stuff into a tiny stuff sack.
I found the snaps that separate the arms from the rest of the poncho often came unsnapped in the wind and sometimes simply in moving around. In a downpour accompanied by wind, the poncho didn't protect me as much as I'd hoped, but I can't imagine any poncho would in such conditions.
I'm 5'4" and 137 lb and the poncho feels very big on me but again, that's to be expected.
Overall, this poncho is good, easy, and lightweight rain protection for me and my backpack.